A magnitude-4.4 earthquake near Mount Cook was a short, sharp jolt that caused no damage.
GeoNet rated the quake at 10:30am today as strong. It was centred 30km northwest of the mountain at a depth of just 4km.
"I was sitting at my desk and it was short and sharp, just a little thud really," Leigh Stock, general manager of the Hermitage Hotel at the base of the mountain, said.
"There was no roll to it, no damage and most of our guests were unaware of it," he said.
The quake was lightly felt around the Fox and Franz Josef glaciers with reports coming from as far north as Greymouth.
It came a week after a 5.7 quake caused cliffs to collapse near Christchurch.
The South Island's biggest city marks the fifth anniversary of the 6.3 quake that killed 185 people on Monday.
Mount Cook is a major tourist destination in the South Island and many people travel to it via Christchurch.